in which,on which怎么应用

高中定语从句中的这两个怎么用法，有什么区别。我只知道why相当于for which= =

in which等于where

on which等于when

for which等于why

介词加关系代词的用法。 那要看具体的句子。 介词的选择要看它在从句中的搭配

　This is the house in which I lived two years ago. 这是我两年前住过的房子。

 从句还原应该是 i lived in the house two years ago.

    the house 被which取代  而在从句中它又和in搭配

另外， in the house 在从句中做地点状语， 所以这里的in which =where

　　所以也可以这样说  This is the house where I lived two years ago.

同理，Do you remember the day on which you joined our club？ 还记得你加入我们俱乐部的那一天吗？

 从句还原应该是you joined our club on the day

    the day被which取代  而在从句中on和 the day搭配

    on the day 在从句中做时间状语， 所以这里的on which =when

  所以也可以这样说

　　Do you remember the day when you joined our club？

用什么介词关键要看先行词和从句的固定搭配。介词的选择要从以下三个方面来考虑：

1）根据从句中动词、形容词、名词与介词的固定搭配而定。如：

The house in which I live is very large.

He has found a good job for which he is qualified.

2）根据先行词与从句中的动词关系及其所表达的含义而定。如：

The pen with which I am writing is borrowed from my classmate Tom.

3）根据先行词在定语从句中的作用与含义而定。如：

The science of medicine, in which progress has been very rapid lately, is perhaps the most important of all the science. 

注意：“ 介词+which/whom”结构中的关系代词不能省略。